Multilayer ceramic capacitor and method of manufacturing the same

ABSTRACT

A multilayer ceramic capacitor includes: a ceramic body including dielectric layers and having first and second surfaces opposing each other, third and fourth surfaces connecting the first and second surfaces to each other, and fifth and sixth surfaces connected to the first to fourth surfaces and opposing each other; a plurality of internal electrodes disposed in the ceramic body, exposed to the first and second surfaces, and having one ends exposed to the third or fourth surface; and a first side margin portion and a second side margin portion disposed, respectively, on side portions of the internal electrodes exposed to the first and second surfaces. A thickness of each of the first and second side margin portions is 10 μm or more and less than 45 μm.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims benefit of priority to Korean Patent ApplicationNo. 10-2018-0102123 filed on Aug. 29, 2018 in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a multilayer ceramic capacitor capableof having improved moistureproof reliability by controlling a thicknessof a side margin portion disposed on a side surface of a ceramic body toprevent the permeation of moisture, and a method of manufacturing thesame.

BACKGROUND

Generally, electronic components using a ceramic material, such as acapacitor, an inductor, a piezoelectric element, a varistor, athermistor, and the like, include a ceramic body formed of the ceramicmaterial, internal electrodes formed in the ceramic body, and externalelectrodes disposed on surfaces of the ceramic body to be connected tothe internal electrodes.

Recently, in accordance with miniaturization and multi-functionalizationof electronic products, multilayer ceramic electronic components alsotend to be miniaturized and multi-functionalized. Therefore, amultilayer ceramic capacitor having a small size and a high capacitancehas been demanded.

In order to miniaturize the multilayer ceramic capacitor and increase acapacitance of the multilayer ceramic capacitor, it has been required tosignificantly increase an electrode effective area (increase aneffective volume fraction required for implementing a capacitance).

In order to implement the miniature and high-capacitance multilayerceramic capacitor as described above, in manufacturing the multilayerceramic capacitor, a method of significantly increasing areas ofinternal electrodes in a width direction of a body through a design thatdoes not have a margin by exposing the internal electrodes in the widthdirection of the body and completing the multilayer ceramic capacitor byseparately attaching side margin portions to electrode exposed surfacesof the multilayer ceramic capacitor in the width direction in a processbefore sintering after the multilayer ceramic capacitor is manufacturedhas been used.

However, in such a method, in a process of forming the side marginportion, when a thickness of the side margin portion is excessively low,moisture may permeate into the body, such that moistureproof reliabilitymay be decreased.

Therefore, research into technology capable of improving moistureproofreliability of a subminiature and high-capacitance multilayer ceramiccapacitor has been required.

SUMMARY

An aspect of the present disclosure may provide a multilayer ceramiccapacitor capable of having improved moistureproof reliability bycontrolling a thickness of a side margin portion disposed on a sidesurface of a ceramic body to prevent permeation of moisture, and amethod of manufacturing the same.

According to an aspect of the present disclosure, a multilayer ceramiccapacitor may include: a ceramic body including dielectric layers andhaving first and second surfaces opposing each other, third and fourthsurfaces connecting the first and second surfaces to each other, andfifth and sixth surfaces connected to the first to fourth surfaces andopposing each other; a plurality of internal electrodes disposed in theceramic body, exposed to the first and second surfaces, and having oneends exposed to the third or fourth surface; and a first side marginportion and a second side margin portion disposed, respectively, on sideportions of the internal electrodes exposed to the first and secondsurfaces. A thickness of each of the first and second side marginportions may be 10 μm or more and less than 45 μm.

According to another aspect of the present disclosure, a method ofmanufacturing a multilayer ceramic capacitor may include: preparingfirst ceramic green sheets on which a plurality of first internalelectrodes patterns are formed at predetermined intervals and secondceramic green sheets on which a plurality of second internal electrodespatterns are formed at predetermined intervals; forming a ceramic greensheet multilayer body by stacking the first and second ceramic greensheets so that the first internal electrodes patterns and the secondinternal electrodes patterns intersect each other; cutting the ceramicgreen sheet multilayer body to have side surfaces on which distal endsof the first internal electrodes patterns and the second internalelectrodes patterns are exposed in a width direction; forming a firstside margin portion and a second side margin portion, respectively, onthe side surfaces to which the distal ends of the first internalelectrodes patterns and the second internal electrodes patterns areexposed; and preparing a ceramic body including dielectric layers andinternal electrodes by sintering the cut ceramic green sheet multilayerbody. A thickness of each of the first and second side margin portionsmay be 10 μm or more and less than 45 μm.

BRIEF DESCRIPTION OF DRAWINGS

The above and other aspects, features, and advantages of the presentdisclosure will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 is a schematic perspective view illustrating a multilayer ceramiccapacitor according to an exemplary embodiment in the presentdisclosure;

FIG. 2 is a perspective view illustrating an appearance of a ceramicbody of FIG. 1;

FIG. 3 is a perspective view illustrating a ceramic green sheetmultilayer body before the ceramic body of FIG. 2 is sintered;

FIG. 4 is a side view when viewed in direction B of FIG. 2; and

FIGS. 5A through 5F are schematic cross-sectional views and schematicperspective views illustrating a method of manufacturing a multilayerceramic capacitor according to another exemplary embodiment in thepresent disclosure.

DETAILED DESCRIPTION

Hereinafter, exemplary embodiments of the present disclosure will now bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic perspective view illustrating a multilayer ceramiccapacitor according to an exemplary embodiment in the presentdisclosure.

FIG. 2 is a perspective view illustrating an appearance of a ceramicbody of FIG. 1.

FIG. 3 is a perspective view illustrating a ceramic green sheetmultilayer body before the ceramic body of FIG. 2 is sintered.

FIG. 4 is a side view when viewed in direction B of FIG. 2.

Referring to FIGS. 1 through 4, a multilayer ceramic capacitor 100according to the present exemplary embodiment may include a ceramic body110, a plurality of internal electrodes 121 and 122 formed in theceramic body 110, and external electrodes 131 and 132 formed on outersurfaces of the ceramic body 110.

The ceramic body 110 may have first and second surfaces 1 and 2 opposingeach other, third and fourth surfaces 3 and 4 connecting the first andsecond surfaces to each other, and fifth and sixth surfaces 5 and 6,which are upper and lower surfaces, respectively.

The first and second surfaces 1 and 2 refer to surfaces of the ceramicbody 110 opposing each other in a width direction W, which is a seconddirection, the third and fourth surfaces 3 and 4 refer to surfaces ofthe ceramic body 110 opposing each other in a length direction L, whichis a first direction, and the fifth and sixth surfaces 5 and 6 refer tosurfaces of the ceramic body 110 opposing each other in a thicknessdirection T, which is a third direction.

A shape of the ceramic body 110 is not particularly limited, but may bea rectangular parallelepiped shape as illustrated.

One ends of the plurality of internal electrodes 121 and 122 formed inthe ceramic body 110 may be exposed to the third surface 3 or the fourthsurface 4 of the ceramic body.

The internal electrodes 121 and 122 may have a pair of first and secondinternal electrodes 121 and 122 having different polarities.

One ends of the first internal electrodes 121 may be exposed to thethird surface 3, and one ends of the second internal electrodes 122 maybe exposed to the fourth surface 4.

The other ends of the first internal electrodes 121 may be spaced apartfrom the fourth surface 4 by a predetermined interval. The other ends ofthe second internal electrodes 122 may be spaced apart from the thirdsurface 3 by a predetermined interval.

First and second external electrodes 131 and 132 may be formed on thethird and fourth surfaces 3 and 4 of the ceramic body, respectively, andmay be electrically connected to the internal electrodes.

The multilayer ceramic capacitor 100 according to an exemplaryembodiment in the present disclosure may include the plurality ofinternal electrodes 121 and 122 disposed in the ceramic body 110,exposed to the first and second surfaces 1 and 2, and having one endsexposed to the third surface 3 or the fourth surface 4, and first andsecond side margin portions 112 and 113 disposed on side portions of theinternal electrodes 121 and 122 exposed to the first and second surfaces1 and 2, respectively.

The plurality of internal electrodes 121 and 122 may be formed in theceramic body 110, the respective side portions of the plurality ofinternal electrodes 121 and 122 may be exposed to the first and secondsurfaces 1 and 2, which are surfaces of the ceramic body 110 in thewidth direction, and the first and second side margin portions 112 and113 may be disposed on the exposed side portions.

An average thickness tc of each of the first and second side marginportions 112 and 113 may be 10 μm or more and less than 45 μm.

According to an exemplary embodiment in the present disclosure, theceramic body 110 may include a laminate in which a plurality ofdielectric layers 111 are stacked and the first and second side marginportions 112 and 113 disposed on opposite side surfaces of the laminate,respectively.

The plurality of dielectric layers 111 may be in a sintered state, andadjacent dielectric layers may be integrated with each other so thatboundaries therebetween are not readily apparent.

A length of the ceramic body 110 may correspond to a distance from thethird surface 3 of the ceramic body to the fourth surface 4 of theceramic body.

A length of the dielectric layer 111 may form a distance between thethird and fourth surfaces 3 and 4 of the ceramic body.

According to an exemplary embodiment in the present disclosure, thelength of the ceramic body may be 400 to 1400 μm, but is not limitedthereto. More specifically, the length of the ceramic body may be 400 to800 μm or may be 600 to 1400 μm.

The internal electrodes 121 and 122 may be formed on the dielectriclayers 111, and the internal electrodes 121 and 122 may be formed in theceramic body with each of the dielectric layers interposed therebetween,by sintering.

Referring to FIG. 3, the first internal electrodes 121 may be formed onthe dielectric layers 111. The first internal electrodes 121 may not beentirely formed on the dielectric layers in the length direction of thedielectric layers. That is, one end of the first internal electrode 121may be formed up to the third surface 3 to be exposed to the thirdsurface 3, and the other end of the first internal electrode 121 may beformed to be spaced apart from the fourth surface of the ceramic body bya predetermined interval.

The end portion of the first internal electrode exposed to the thirdsurface 3 of the ceramic body may be connected to the first externalelectrode 131.

On the contrary to the first internal electrode, one end of the secondinternal electrode 122 may be exposed to the fourth surface 4 to beconnected to the second external electrode 132, and the other end of thesecond internal electrode 122 may be formed to be spaced apart from thethird surface 3 by a predetermined interval.

Four hundred or more internal electrodes may be stacked in order toimplement a high-capacitance multilayer ceramic capacitor, but thenumber of internal electrodes is not necessarily limited thereto.

The dielectric layer 111 may have the same width as that of the firstinternal electrode 121. That is, the first internal electrodes 121 maybe entirely formed on the dielectric layers in the width direction ofthe dielectric layers 111. The dielectric layer 111 may have the samewidth as that of the second internal electrode 122. That is, the secondinternal electrodes 122 may be entirely formed on the dielectric layersin the width direction of the dielectric layers 111.

According to an exemplary embodiment in the present disclosure, thewidth of the dielectric layer and the width of the internal electrodemay be 100 to 900 μm, but are not limited thereto. More specifically,the width of the dielectric layer and the width of the internalelectrode may be 100 to 500 μm or may be 100 to 900 μm.

As the ceramic body is miniaturized, a thickness of each of the sidemargin portions may have an influence on electrical characteristics ofthe multilayer ceramic capacitor. According to an exemplary embodimentin the present disclosure, each of the side margin portions may beformed at a thickness less than 45 μm, such that moistureproofcharacteristics and other electrical characteristics of a miniaturizedmultilayer ceramic capacitor may be improved.

That is, each of the side margin portions may be formed at the thicknessless than 45 μm, such that an overlapping area between the internalelectrodes forming a capacitance may be secured as much as possible toimplement a high-capacitance and miniature multilayer ceramic capacitor.In addition, each of the side margin portions may be formed at thethickness less than 45 μm, such that permeation of moisture into theceramic body may be prevented to improve moistureproof reliability ofthe multilayer ceramic capacitor.

The ceramic body 110 may include an active portion A contributing toforming a capacitance of a capacitor, and upper and lower cover portions114 and 115 formed as upper and lower margin portions on upper and lowersurfaces of the active portion A, respectively.

The active portion A may be formed by repeatedly stacking a plurality offirst and second internal electrodes 121 and 122 with each of thedielectric layers 111 interposed therebetween.

The upper and lower cover portions 114 and 115 may be formed of the samematerial as that of the dielectric layer 111 and have the sameconfiguration as that of the dielectric layer 111 except that they donot include the internal electrodes.

That is, the upper and lower cover portions 114 and 115 may include aceramic material such as a barium titanate (BaTiO₃)-based ceramicmaterial.

Each of the upper and lower cover portions 114 and 115 may have athickness of 20 μm or less, but is not necessarily limited thereto.

In an exemplary embodiment in the present disclosure, the internalelectrodes and the dielectric layers, which are simultaneously cut andformed, may be formed at the same width. More detailed contents for thiswill be described below.

In the present exemplary embodiment, the dielectric layers may be formedat the same width as that of the internal electrodes, and the sideportions of the internal electrodes 121 and 122 may thus be exposed tothe first and second surfaces of the ceramic body 110 in the widthdirection.

The first and second side margin portions 112 and 113 may be formed,respectively, on opposite side surfaces of the ceramic body 110 in thewidth direction to which the side portions of the internal electrodes121 and 122 are exposed.

Each of the first and second side margin portions 112 and 113 may havethe thickness less than 45 μm. The smaller the thickness of each of thefirst and second side margin portions 112 and 113, the greater theoverlapping area between the internal electrodes formed in the ceramicbody.

The thickness of each of the first and second side margin portions 112and 113 is not particularly limited as long as a short-circuit betweenthe internal electrodes exposed to the side surfaces of the ceramic bodymay be prevented, and may be, for example, 10 μm or more.

When the thickness of each of the first and second side margin portions112 and 113 is 10 μm, a moisture permeability rate may be substantially0.

When the thickness of each of the first and second side margin portions112 and 113 is less than 10 μm, the thickness of each of the first andsecond side margin portions 112 and 113 may be small, such that moisturemay permeate into the ceramic body through the side margin portions todecrease the moistureproof reliability.

Meanwhile, when the thickness of each of the first and second sidemargin portions 112 and 113 is 45 μm or more, the overlapping areabetween the internal electrodes may be relatively decreased, such thatit may be difficult to secure a high capacitance of the multilayerceramic capacitor.

In addition, sintering may not be sufficiently performed at the samesintering temperature in a case in which the thickness of each of thefirst and second side margin portions 112 and 113 is 45 μm or more ascompared to a case in which when the thickness of each of the first andsecond side margin portions 112 and 113 is less than 45 μm, such thatpores may be generated in a surface of each of the first and second sidemargin portions 112 and 113 to increase a surface moisture absorptivity.Therefore, moistureproof reliability may be decreased.

In order to significantly increase a capacitance of the multilayerceramic capacitor, a method of decreasing a thickness of each of thedielectric layers, a method of increasing the number of stackeddielectric layers each of which a thickness is decreased, a method ofincreasing a coverage of each of the internal electrodes, and the like,have been considered.

In addition, a method of increasing the overlapping area between theinternal electrodes forming the capacitance has been considered.

In order to increase the overlapping area between the internalelectrodes, a margin portion region in which the internal electrodes arenot formed needs to be significantly decreased.

Particularly, as the multilayer ceramic capacitor is miniaturized, themargin portion region needs to be significantly decreased in order toincrease the overlapping area between the internal electrodes.

Generally, as the number of stacked dielectric layers is increased,thicknesses of the dielectric layers and the internal electrodes may bedecreased. Therefore, a phenomenon in which the internal electrodes areshort-circuited may frequently occur. In addition, when the internalelectrodes are formed on only portions of the dielectric layers, a stepdue to the internal electrodes may be generated, such that an insulationresistance or reliability of the multilayer ceramic capacitor may bedecreased.

However, according to the present exemplary embodiment, even though theinternal electrodes and the dielectric layers formed of thin films areformed, the internal electrodes may be entirely formed on the dielectriclayers in the width direction of the dielectric layers, and theoverlapping area between the internal electrodes may thus be increased,such that the capacitance of the multilayer ceramic capacitor may beincreased.

In addition, the step due to the internal electrodes may be decreased,such that the insulation resistance may be improved, and a multilayerceramic capacitor having excellent capacitance characteristics andexcellent reliability may be provided.

According to the present exemplary embodiment, the internal electrodesmay be formed over the entirety of the dielectric layers in the widthdirection of the dielectric layers, and each of the side margin portionsmay be set to 10 μm or more and less than 45 μm, such that theoverlapping area between the internal electrodes may be great.

Therefore, a subminiature and high-capacitance multilayer ceramiccapacitor may be implemented, and moistureproof reliability may also beimproved.

Particularly, the multilayer ceramic capacitor according to an exemplaryembodiment in the present disclosure may be a subminiature andhigh-capacitance multilayer ceramic capacitor in which a thickness ofthe dielectric layer 111 is 0.4 μm or less and a thickness of each ofthe internal electrodes 121 and 122 is 0.4 μm or less.

As in an exemplary embodiment in the present disclosure, in a case ofthe subminiature and high-capacitance multilayer ceramic capacitor inwhich the dielectric layer 111 and the internal electrodes 121 and 122formed of thin films having the thickness of 0.4 μm or less are used, adecrease problem in the moistureproof reliability due to permeation ofmoisture into the side margin portion may be a very important issue.

That is, as compared to the multilayer ceramic capacitor according tothe related art, technology according an exemplary embodiment in thepresent disclosure is applied to the subminiature and high-capacitancemultilayer ceramic capacitor in which the thickness of the dielectriclayer 111 is 0.4 μm or less and the thickness of each of the internalelectrodes 121 and 122 is 0.4 μm or less. Therefore, the thicknesses ofthe dielectric layer and the internal electrodes may be small, resultingin an increase in a possibility that the moistureproof reliability willbe decreased due to the permeation of the moisture.

However, as in an exemplary embodiment in the present disclosure, in thesubminiature and high-capacitance multilayer ceramic capacitor in whichthe separate side margin portions are attached, the average thickness tcof each of the first and second side margin portions 112 and 113 may becontrolled to be 10 μm or more and less than 45 μm, such that themoistureproof reliability may be improved even in a case in which thedielectric layer 111 and the first and second internal electrodes 121and 122 are formed of the thin films having the thickness of 0.4 μm orless.

However, the thin films do not mean that the thicknesses of thedielectric layer 111 and the first and second internal electrodes 121and 122 are 0.4 μm or less, but may conceptually include that thethicknesses of the dielectric layer and the internal electrodes aresmaller than those of the multilayer ceramic capacitor according to therelated art.

Referring to FIG. 4, a ratio of a thickness tc2 of a region of the firstor second side margin portion in contact with a distal end of aninternal electrode disposed at the outermost side portion to a thicknesstc1 of a region of the first or second side margin portion in contactwith a distal end of an internal electrode disposed in a centralportion, among the plurality of internal electrodes 121 and 122, may be1.0 or less.

A lower limit value of the ratio of the thickness tc2 of the region ofthe first or second side margin portion in contact with the distal endof the internal electrode disposed at the outermost side portion to thethickness tc1 of the region of the first or second side margin portionin contact with the distal end of the internal electrode disposed at thecentral portion is not particularly limited, and may be 0.9 or more.

According to an exemplary embodiment in the present disclosure, thefirst or second side margin portion may be formed by attaching a ceramicgreen sheet to the side surface of the ceramic body unlike the relatedart, and a thickness of the first or second side margin portion at eachposition may thus be constant.

That is, in the related art, the side margin portion is formed in amanner of applying or printing a ceramic slurry, and a deviation of athickness of the side margin portion at each position is thus large.

In detail, in the related art, the thickness of the region of the firstor second side margin portion in contact with the distal end of theinternal electrode disposed at the central portion of the ceramic bodyis greater than those of other regions.

For example, in the related art, the ratio of the thickness of theregion of the first or second side margin portion in contact with thedistal end of the internal electrode disposed at the outermost sideportion to the thickness of the region of the first or second sidemargin portion in contact with the distal end of the internal electrodedisposed at the central portion is less than about 0.9, such that thedeviation of the thickness is large.

In the related art in which the deviation of the thickness of the sidemargin portion at each position is large, a portion occupied by the sidemargin portion in a multilayer ceramic capacitor having the same size islarge, such that a large size of a capacitance forming portion may notbe secured, resulting in difficulty in securing a high capacitance.

On the other hand, in an exemplary embodiment in the present disclosure,the average thickness tc of each of the first and second side marginportions 112 and 113 may be 10 μm or more and less than 45 μm, and theratio of the thickness tc2 of the region of the first or second sidemargin portion in contact with the distal end of the internal electrodedisposed at the outermost side portion to the thickness tc1 of theregion of the first or second side margin portion in contact with thedistal end of the internal electrode disposed at the central portionamong the plurality of internal electrodes 121 and 122 may be 0.9 ormore and 1.0 or less. Therefore, the thickness of the side marginportion may be small and the deviation of the thickness of the sidemargin portion may be small, such that a large size of the capacitanceforming portion may be secured.

In an exemplary embodiment in the present disclosure, the first orsecond side margin portion may be formed by attaching the ceramic greensheet to the side surface of the ceramic body unlike the related art,and the thickness of the first or second side margin portion at eachposition may thus be constant.

Therefore, a high-capacitance multilayer ceramic capacitor may beimplemented.

Meanwhile, referring to FIG. 4, a ratio of a thickness tc3 of a regionof the first or second side margin portion in contact with an edge ofthe ceramic body 110 to the thickness tc1 of the region of the first orsecond side margin portion in contact with the distal end of theinternal electrode disposed at the central portion among the pluralityof internal electrodes 121 and 122 may be 1.0 or less.

A lower limit value of the ratio of the thickness tc3 of the region ofthe first or second side margin portion in contact with the edge of theceramic body 110 to the thickness tc1 of the region of the first orsecond side margin portion in contact with the distal end of theinternal electrode disposed at the central portion may be 0.9 or more.

Due to the feature described above, a deviation of the thickness of theside margin portion in each region may be small, such that the largesize of the capacitance forming portion may be secured. Therefore, thehigh-capacitance multilayer ceramic capacitor may be implemented.

FIGS. 5A through 5F are schematic cross-sectional views and schematicperspective views illustrating a method of manufacturing a multilayerceramic capacitor according to another exemplary embodiment in thepresent disclosure.

According to another exemplary embodiment in the present disclosure, amethod of manufacturing a multilayer ceramic capacitor may include:preparing first ceramic green sheets on which a plurality of firstinternal electrodes patterns are formed at predetermined intervals andsecond ceramic green sheets on which a plurality of second internalelectrodes patterns are formed at predetermined intervals, forming aceramic green sheet multilayer body by stacking the first and secondceramic green sheets so that the first internal electrodes patterns andthe second internal electrodes patterns overlap with each other, cuttingthe ceramic green sheet multilayer body to have side surfaces on whichdistal ends of the first internal electrodes patterns and the secondinternal electrodes patterns are exposed in a width direction, forming afirst side margin portion and a second side margin portion,respectively, on the side surfaces to which the distal ends of the firstinternal electrodes patterns and the second internal electrodes patternsare exposed, and preparing a ceramic body including dielectric layersand first and second internal electrodes by sintering the cut ceramicgreen sheet multilayer body. An average thickness tc of each of thefirst side margin portion 112 and the second side margin portion 113 is10 μm or more and less than 45 μm.

The method of manufacturing a multilayer ceramic capacitor according toanother exemplary embodiment in the present disclosure will hereinafterbe described.

As illustrated in FIG. 5A, the plurality of first internal electrodepatterns 221 having a stripe shape may be formed at the predeterminedintervals on the ceramic green sheet 211. The plurality of firstinternal electrode patterns 221 having the stripe shape may be formed inparallel with one another.

The ceramic green sheet 211 may be formed of a ceramic paste includingceramic powders, an organic solvent, and an organic binder.

The ceramic powder, which is a material having a high dielectricconstant, may be a barium titanate (BaTiO₃) based material, a leadcomposite perovskite based material, a strontium titanate (SrTiO₃) basedmaterial, or the like, and may be preferably a barium titanate (BaTiO₃)powder, but is not limited thereto. When the ceramic green sheet 211 issintered, the ceramic green sheet 211 may become a dielectric layer 111constituting the ceramic body 110.

The first internal electrode patterns 221 having the stripe shape may beformed of an internal electrode paste containing a conductive metal. Theconductive metal may be nickel (Ni), copper (Cu), palladium (Pd), oralloys thereof, but is not limited thereto.

A method of forming the first internal electrode patterns 221 having thestripe shape on the ceramic green sheet 211 is not particularly limited,but may be a printing method such as a screen printing method or agravure printing method.

In addition, although not illustrated, the plurality of second internalelectrode patterns 222 having a stripe shape may be formed at thepredetermined intervals interposed therebetween on another ceramic greensheet 211.

Hereinafter, the ceramic green sheet on which the first internalelectrode patterns 221 are formed may be referred to as a first ceramicgreen sheet, and the ceramic green sheet on which the second internalelectrode patterns 222 are formed may be referred to as a second ceramicgreen sheet.

Then, as illustrated in FIG. 5B, the first and second ceramic greensheets may be alternately stacked so that the internal electrodepatterns 221 having the stripe shape and the second internal electrodepatterns 222 having the stripe shape are alternately stacked.

Afterward, the first internal electrode patterns 221 having the stripeshape may become the first internal electrode 121, and the secondinternal electrode patterns 222 having the stripe shape may become thesecond internal electrode 122.

According to another exemplary embodiment in the present disclosure, athickness td of each of the first and second ceramic green sheets may be0.6 μm or less, and a thickness te of each of the first and secondinternal electrode patterns may be 0.5 μm or less.

Since the subminiature and high-capacitance multilayer ceramic capacitorin which the dielectric layer and the internal electrodes are formed ofthe thin films having the thickness of 0.4 μm or less is provided in thepresent disclosure, the thickness td of each of the first and secondceramic green sheets may be 0.6 μm or less, and the thickness te of eachof the first and second internal electrode patterns may be 0.5 μm orless.

FIG. 5C is a cross-sectional view illustrating a ceramic green sheetmultilayer body 220 in which the first and second ceramic green sheetsare stacked according to another exemplary embodiment in the presentdisclosure, and FIG. 5D is a perspective view illustrating the ceramicgreen sheet multilayer body 220 in which the first and second ceramicgreen sheets are stacked.

Referring to FIGS. 5C and 5D, the first ceramic green sheets on whichthe plurality of first internal electrode patterns 221 parallel with oneanother and having the stripe shape are printed and the second ceramicgreen sheets on which the plurality of second internal electrodepatterns 222 having parallel with one another and having the stripeshape are printed may be alternately stacked.

In more detail, the first ceramic green sheets and the second ceramicgreen sheets may be stacked so that central portions of the firstinternal electrode patterns 221 having the stripe shape, printed on thefirst ceramic green sheets and intervals between the second internalelectrode patterns 222 having the stripe shape, printed on the secondceramic green sheets overlap each other.

Then, as illustrated in FIG. 5D, the ceramic green sheet multilayer body220 may be cut across the plurality of first internal electrode patterns221 having the stripe shape and the plurality of second internalelectrode patterns 222 having the stripe shape. That is, the ceramicgreen sheet multilayer body 220 may be cut along cut lines C1-C1 andC2-C2 intersecting with each other to become multilayer bodies 210.

In more detail, the first internal electrode patterns 221 having thestripe shape and the second internal electrode patterns 222 having thestripe shape may be cut in the length direction to be divided into aplurality of internal electrodes having a predetermined width. In thiscase, the stacked ceramic green sheets may be cut together with theinternal electrode patterns. Therefore, the dielectric layers may beformed to have the same width as that of the internal electrodes.

In addition, the ceramic green sheet multilayer body may be cut atindividual ceramic body sizes along the cut lines C2-C2. That is, beforethe first and second side margin portions are formed, a laminate havinga bar shape may be cut at the individual ceramic body sizes along thecut lines C2-C2 to form a plurality of multilayer bodies 210.

That is, the laminate having the bar shape may be cut so that centralportions of the first internal electrodes and predetermined intervalsformed between the second internal electrodes, which overlap each other,are cut by the same cut lines. Therefore, one ends of the first andsecond internal electrodes may be alternately exposed to cut surfaces.

Then, the first and second side margin portions may be formed on firstand second side surfaces of the multilayer body 210.

Then, as illustrated in FIG. 5E, the first side margin portion 212 andthe second side margin portion (not illustrated) may be formed on thefirst and second side surfaces of the multilayer body 210, respectively.

In detail, in a method of forming the first side margin portion 212, aceramic green sheet 212 for a side surface to which an adhesive (notillustrated) is applied may be disposed on a punching elastic material300 formed of rubber.

Then, the multilayer body 210 may be rotated by 90° so that the firstside surface of the multilayer body 210 faces the ceramic green sheet212 for a side surface to which the adhesive (not illustrated) isapplied, and the multilayer body 210 may then be pressed and closelyadhered to the ceramic green sheet 212 for a side surface to which theadhesive (not illustrated) is applied.

When the ceramic green sheet 212 for a side surface is transferred tothe multilayer body 210 by pressing and closely adhering the multilayerbody 210 to the ceramic green sheet 212 for a side surface to which theadhesive (not illustrated) is applied, the ceramic green sheet 212 for aside surface may be formed up to an edge portion of the side surface ofthe multilayer body 210 due to the punching elastic material 300 formedof the rubber, and the remaining portions may be cut.

FIG. 5F illustrates that the ceramic green sheet 212 for a side surfaceis formed up to the edge portion of the side surface of the multilayerbody 210.

Then, the multilayer body 210 may be rotated, and the second side marginportion may be formed on the second side surface of the multilayer body210.

Then, the multilayer body 210 having the first and second side marginportions formed on opposite side surfaces thereof, respectively, may becalcinated and sintered to form the ceramic body including thedielectric layers and the first and second internal electrodes.

According to another exemplary embodiment in the present disclosure, theadhesive is applied to the ceramic green sheet 212 for a side surface,and the ceramic green sheet 212 for a side surface may thus betransferred to the side surface of the multilayer body 210 under a lowtemperature and low pressure condition unlike the related art.

Therefore, damage to the multilayer body 210 may be significantlydecreased, such that deterioration of electrical characteristics of themultilayer ceramic capacitor after the sintering may be prevented, andreliability of the multilayer ceramic capacitor may be improved.

In addition, the ceramic green sheet 212 for a side surface to which theadhesive is applied may be transferred to the side surface of themultilayer body 210 and be pressed in a sintering process to increaseclose adhesion between the multilayer body and the ceramic green sheetfor a side surface.

Then, external electrodes may be formed, respectively, on the third sidesurface of the ceramic body to which the first internal electrodes areexposed and the fourth side surface of the ceramic body to which thesecond internal electrodes are exposed.

According to another exemplary embodiment in the present disclosure, athickness of the ceramic green sheet for a side surface may be small anda deviation of the thickness of the ceramic green sheet for a sidesurface may be small, such that the large size of the capacitanceforming portion may be secured.

In detail, an average thickness tc of each of the first and second sidemargin portions 112 and 113 after the sintering may be 10 μm or more andless than 45 μm, and the deviation of the thickness of each of the firstand second side margin portions 112 and 113 at each position may besmall, such that the large size of the capacitance forming portion maybe secured, and the moistureproof reliability may be excellent.

Therefore, a high-capacitance multilayer ceramic capacitor may beimplemented.

A description for features that are the same as those in the exemplaryembodiment in the present disclosure described above will be omitted inorder to avoid an overlapping description.

Hereinafter, the present disclosure will be described in more detailthrough Experimental Example. However, Experimental Example is to assistin the detailed understanding of the present disclosure, and the scopeof the present disclosure is not limited by Experimental Example.

EXPERIMENTAL EXAMPLE

Multilayer ceramic capacitors according to Inventive Examples 1 and 2were manufactured so that the average thicknesses tc of each of thefirst and second side margin portions 112 and 113 are 10 μm and 25 μm,and a multilayer ceramic capacitor according to Comparative Example wasmanufactured so that the average thickness of each of the first andsecond side margin portions is 45 μm.

In addition, ceramic green sheet multilayer bodies were formed to formside margin portions by attaching ceramic green sheets for a sidesurface to electrode exposed portions of green chips that do not havemargins due to exposure of internal electrodes in a width direction asin Comparative Example and Inventive Example.

Multilayer ceramic capacitor green chips having a 0603 size(width×length×height is 0.6 mm×0.3 mm×0.3 mm) were manufactured byapplying a predetermined temperature and pressure under a condition inwhich deformation of the chips is significantly suppressed to attach theceramic green sheets for a side surface to opposite surfaces of theceramic green sheet multilayer bodies.

Multilayer ceramic capacitor specimens of which the manufacture iscompleted as described above were subjected to a calcinating process ina nitrogen atmosphere at 400° C. or less, and were sintered under acondition of a hydrogen concentration of 0.5% H₂ or less at a sinteringtemperature of 1200° C. or less. Then, moisture permeability rates ofthe multilayer ceramic capacitor specimens were confirmed.

Measurement of the moisture permeability rates was performed byobserving the multilayer ceramic capacitors according to ComparativeExample and Inventive Examples 1 and 2 at a temperature of 160° C. and arelative humidity of 90% for 300 minutes.

TABLE 1 Thickness (μm) of Moisture Permeability Side Margin Portion Rate(wt %) Inventive 10 0.001 Example 1 Inventive 25 0.002 Example 2Comparative 45 0.783 Example

As a measurement result of the above experiment, it may be seen that inInventive Examples 1 and 2, moisture permeability rates have valuesalmost close to 0, such that moistureproof reliability is excellent.

On the other hand, it may be seen that in Comparative Example, amoisture permeability rate is high (0.783 wt %), such that moistureproofreliability is low.

It proved that in Comparative Example, a case in which the multilayerceramic capacitor is manufactured so that the average thickness of eachof the first and second side margin portions is 45 μm, such that theaverage thickness of each of the first and second side margin portionsis 45 μm or more, sintering is not sufficiently performed, such thatpores are generated in an inner portion and a surface of each of theside margin portions and moisture thus permeates into the multilayerceramic capacitor.

As set forth above, according to an exemplary embodiment in the presentdisclosure, the thickness of the side margin portion disposed on theside surface of the ceramic body may be controlled to prevent thepermeation of the moisture, resulting in improvement of themoistureproof reliability.

While exemplary embodiments have been shown and described above, it willbe apparent to those skilled in the art that modifications andvariations could be made without departing from the scope of the presentinvention as defined by the appended claims.

What is claimed is:
 1. A multilayer ceramic capacitor comprising: aceramic body including dielectric layers and having first and secondsurfaces opposing each other, third and fourth surfaces connecting thefirst and second surfaces to each other, and fifth and sixth surfacesconnected to the first to fourth surfaces and opposing each other; aplurality of internal electrodes including 400 or more internalelectrodes each having a thickness of 0.4 μm or less, each disposed inthe ceramic body, each exposed to the first and second surfaces, eachhaving one end exposed to the third or fourth surface, and each beingspaced apart from one or more adjacent internal electrodes by athickness of a dielectric layer of 0.4 μm or less; a first side marginportion and a second side margin portion disposed on the first andsecond surfaces of the ceramic body, respectively, to face side portionsof the internal electrodes exposed to the first and second surfaces,respectively; an adhesive disposed between each of the first and secondside margin portions and the respective first and second surfaces of theceramic body to contact side surfaces of each of the 400 or moreinternal electrodes each having the thickness of 0.4 μm or less and sidesurfaces of each of the dielectric layers having the thickness of 0.4 μmor less; and first and second external electrodes disposed on the thirdand fourth surfaces of the ceramic body, respectively, and eachextending onto surfaces of the first and second side margin portionsother than surfaces of the first and second side margin portionscontacting the adhesive, wherein a thickness of each of the first andsecond side margin portions is 10 μm to 25 μm, wherein each of the firstand second external electrodes includes band portions respectivelyextending a substantially equal distance on the first, second, fifth andsixth surfaces of the ceramic body, wherein cover portions are formed onupper and lower surfaces of an active portion, respectively, wherein athickness of each of the cover portions is 20 μm or less, and wherein aratio of a thickness of a region of the first or second side marginportion in contact with a distal end of an internal electrode disposedat an outermost side portion to a thickness of a region of the first orsecond side margin portion in contact with a distal end of an internalelectrode disposed in a central portion, among the plurality of internalelectrodes, is 0.9 to 1.0.
 2. The multilayer ceramic capacitor of claim1, wherein a ratio of a thickness of a region of the first or secondside margin portion in contact with an edge of the ceramic body to athickness of a region of the first or second side margin portion incontact with a distal end of an internal electrode disposed in a centralportion, among the plurality of internal electrodes, is 0.9 to 1.0. 3.The multilayer ceramic capacitor of claim 1, wherein the active portionhas a capacitance formed by including the plurality of internalelectrodes disposed to face each other with each of the dielectriclayers interposed therebetween.
 4. A method of manufacturing amultilayer ceramic capacitor, comprising: preparing first ceramic greensheets each having a thickness of 0.6 μm or less and on which aplurality of first internal electrodes patterns each having a thicknessof 0.5 μm or less are formed at predetermined intervals and secondceramic green sheets each having a thickness of 0.6 μm or less and onwhich a plurality of second internal electrodes patterns each having athickness of 0.5 μm or less are formed at predetermined intervals;forming a ceramic green sheet multilayer body by stacking 400 or more ofthe first and second ceramic green sheets so that the first internalelectrodes patterns and the second internal electrodes patterns overlapwith each other; cutting the ceramic green sheet multilayer body to haveside surfaces on which distal ends of the first internal electrodespatterns and the second internal electrodes patterns are exposed in awidth direction; applying an adhesive to respective surfaces of thirdand fourth ceramic green sheets; adhering the third and fourth ceramicgreen sheets having the adhesive applied thereto to respective sidesurfaces of the ceramic green sheet multilayer body to which the distalends of the 400 or more of the first internal electrodes patterns andthe second internal electrodes patterns are exposed to form a first sidemargin portion and a second side margin portion, respectively; andpreparing a ceramic body including dielectric layers and internalelectrodes by sintering the cut ceramic green sheet multilayer body,wherein a thickness of each of the first and second side margin portionsis 10 μm to 25 μm, wherein the first side margin portion is formed byadhering a portion of the third ceramic green sheet to one of the sidesurfaces of the cut ceramic green sheet multilayer body using theadhesive, and the second side margin portion is formed by adhering aportion of the fourth ceramic green sheet to another of the sidesurfaces of the cut ceramic green sheet multilayer body using theadhesive, wherein each of first and second external electrodes disposedon third and fourth surfaces of the ceramic body, respectively, includesband portions respectively extending a substantially equal distance onfirst, second, fifth and sixth surfaces of the ceramic body, whereincover portions are formed on upper and lower surfaces of an activeportion, respectively, wherein a thickness of each of the cover portionsis 20 μm or less, and wherein a ratio of a thickness of a region of thefirst or second side margin portion in contact with a distal end of aninternal electrode disposed at an outermost side portion of the ceramicbody to a thickness of a region of the first or second side marginportion in contact with a distal end of an internal electrode disposedat a central portion of the ceramic body among the internal electrodesis 0.9 to 1.0.
 5. The method of claim 4, wherein a ratio of a thicknessof a region of the first or second side margin portion in contact withan edge of the ceramic green sheet multilayer body to a thickness of aregion of the first or second side margin portion in contact with adistal end of an internal electrode disposed in a central portion, amongthe internal electrodes, is 0.9 to 1.0.
 6. The method of claim 4,wherein the active portion has a capacitance formed by including theinternal electrodes disposed to face each other with each of thedielectric layers interposed therebetween.